SAE J1939-71 Message ID

[mmt1357]

Hello all;

A message ID comprises 8 digits such as "AB CD EF GH". When I know PGN number, I can know what "CD EF" is. Likely, when I know Data Page, Default Priority and Reserved Situation, I can know what "AB" is. However, I cannot understand from the J1939-71 standard what digits of "GH" called Source Address is. I need to reach messages but I need whole message ID.

I am currently preparing small .dbc file for some messages and I do not know which message has which source address. 

As I know, parameter group number is unique for messages. Is it possible to use only PGN number to take messages with .dbc file.

I am using Kvaser Data Logger and Kvaser Database Editor. 

Thank you for your help.

Have a good day. 

[mmt1357]

By the way, I will use .dbc file with DIADEM

[cweeks12]

Hi mmt, 

Can you link to where that standard is/where you're finding that information on the spec? That would help anyone that wants to help you out see what exactly you're referring to in this situation.

[mmt1357]

Hello Connor,

Actually, this standard, J1939-71, is sold by SAE. However, I can add a link I found on the internet. Nevertheless, I do not know whether it is legal or not. You evaluate it. I add it to help people here.

https://gurtam.com/files/ftp/CAN/j1939-71.pdf 

By the way, I found the answer. I was wrong. PGN number is unique but it might be come from engine as well as transmission. We need to know source ID. To learn if the message come from any source, we need to look at that source's standard.

For instance, message ID is "AB CD EF GH". You can find what "AB" is by receiving help from J1939-71. "CD EF" is already given. And "GH" is source address. Source's address need to be specified by source's standard. It means that there is no any unique source address related to one message ID. It is possible to have both "AB CD EF 00" or "AB CD EF 03"

Thank you for your help.

Have a good day.

[cweeks12]

mmt,

I'm glad you were able to find the answer! Make sure to mark your post as the solution so anyone else that is wondering the same thing can find your answer.